From c4c47a84a16a29d7077f537051d90de1f3475957 Mon Sep 17 00:00:00 2001
From: Claudiu Zissulescu <claziss@synopsys.com>
Date: Mon, 14 Jun 2021 15:33:17 +0300
Subject: [PATCH] arc: Add --with-fpu support for ARCv2 cpus

Support for a compile-time default FPU. The --with-fpu configuration
option is ignored if -mfpu compiler option is specified. The FPU
options are only available for ARCv2 cpus.

gcc/
2021-06-14  Claudiu Zissulescu  <claziss@synopsys.com>

	* config.gcc (arc): Add support for with_cpu option.
	* config/arc/arc.h (OPTION_DEFAULT_SPECS): Add fpu.

Signed-off-by: Claudiu Zissulescu <claziss@synopsys.com>
---
 gcc/config.gcc       | 44 +++++++++++++++++++++++++++++++++++++++-----
 gcc/config/arc/arc.h |  4 ++++
 2 files changed, 43 insertions(+), 5 deletions(-)

diff --git a/gcc/config.gcc b/gcc/config.gcc
index 4dc4fe0b65c0..1be8d96f5e5a 100644
--- a/gcc/config.gcc
+++ b/gcc/config.gcc
@@ -4260,18 +4260,52 @@ case "${target}" in
 		;;
 
 	arc*-*-*)
-		supported_defaults="cpu"
+		supported_defaults="cpu fpu"
 
+		new_cpu=hs38_linux
 		if [ x"$with_cpu" = x ] \
-		    || grep "^ARC_CPU ($with_cpu," \
-		       ${srcdir}/config/arc/arc-cpus.def \
-		       > /dev/null; then
+		    || grep -q -E "^ARC_CPU[[:blank:]]*\($with_cpu," \
+		       ${srcdir}/config/arc/arc-cpus.def
+		then
 		 # Ok
-		 true
+		 new_cpu=$with_cpu
 		else
 		 echo "Unknown cpu used in --with-cpu=$with_cpu" 1>&2
 		 exit 1
 		fi
+
+		# see if --with-fpu matches any of the supported FPUs
+		case "$with_fpu" in
+		"")
+			# OK
+			;;
+		fpus | fpus_div | fpus_fma | fpus_all)
+			# OK if em or hs
+			flags_ok="[emhs]+"
+			;;
+		fpuda | fpuda_div | fpuda_fma | fpuda_all)
+			# OK only em
+			flags_ok="em"
+			;;
+		fpud | fpud_div | fpud_fma | fpud_all)
+			# OK only hs
+			flags_ok="hs"
+			;;
+		*)
+			echo "Unknown floating point type used in "\
+			     "--with-fpu=$with_fpu" 1>&2
+			exit 1
+			;;
+		esac
+
+		if [ -n "$flags_ok" ] \
+		   && ! grep -q -E "^ARC_CPU[[:blank:]]*\($new_cpu,[[:blank:]]*$flags_ok," \
+		   ${srcdir}/config/arc/arc-cpus.def
+		then
+		   echo "Unknown floating point type used in "\
+			 "--with-fpu=$with_fpu for cpu $new_cpu" 1>&2
+			 exit 1
+		fi
 		;;
 
     csky-*-*)
diff --git a/gcc/config/arc/arc.h b/gcc/config/arc/arc.h
index 0224ae65074f..8cd63500044a 100644
--- a/gcc/config/arc/arc.h
+++ b/gcc/config/arc/arc.h
@@ -100,7 +100,11 @@ extern const char *arc_cpu_to_as (int argc, const char **argv);
   "%:cpu_to_as(%{mcpu=*:%*}) %{mspfp*} %{mdpfp*} "                      \
   "%{mfpu=fpuda*:-mfpuda} %{mcode-density}"
 
+/* Support for a compile-time default CPU and FPU.  The rules are:
+   --with-cpu is ignored if -mcpu, mARC*, marc*, mA7, mA6 are specified.
+   --with-fpu is ignored if -mfpu is specified.  */
 #define OPTION_DEFAULT_SPECS						\
+  {"fpu", "%{!mfpu=*:-mfpu=%(VALUE)}"},					\
   {"cpu", "%{!mcpu=*:%{!mARC*:%{!marc*:%{!mA7:%{!mA6:-mcpu=%(VALUE)}}}}}" }
 
 #ifndef DRIVER_ENDIAN_SELF_SPECS
-- 
2.47.2